Nanowire Failure: Long = Brittle and Short = Ductile
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- 作者：Zhaoxuan Wu ; Yong-Wei Zhang ; Mark H. Jhon ; Huajian Gao ; David J. Srolovitz
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：February 8, 2012
- 年：2012
- 卷：12
- 期：2
- 页码：910-914
- 全文大小：309K
- 年卷期：v.12,no.2(February 8, 2012)
- ISSN：1530-6992
文摘
Experimental studies of the tensile behavior of metallic nanowires show a wide range of failure modes, ranging from ductile necking to brittle/localized shear failure鈥攐ften in the same diameter wires. We performed large-scale molecular dynamics simulations of copper nanowires with a range of nanowire lengths and provide unequivocal evidence for a transition in nanowire failure mode with change in nanowire length. Short nanowires fail via a ductile mode with serrated stress鈥搒train curves, while long wires exhibit extreme shear localization and abrupt failure. We developed a simple model for predicting the critical nanowire length for this failure mode transition and showed that it is in excellent agreement with both the simulation results and the extant experimental data. The present results provide a new paradigm for the design of nanoscale mechanical systems that demarcates graceful and catastrophic failure.